1. Technical Field
The present invention relates to an endoscopic image display apparatus which reads taken image data in which a taken image outputted from an endoscope has been recorded, and displays the taken image.
2. Description of Related Art
Endoscopes which can take an image by irradiating the inside of a to-be-inspected body with white illumination light to thereby obtain an observed image are widely used. In addition to normal imaging with visible light, some endoscopes can perform narrow-band imaging in which short-wavelength visible narrow-band light (special light) is radiated so that capillary blood vessels in a body tissue surface layer or microscopic patterns in a mucosal surface can be highlighted and displayed (for example, see JP-2006-068113-A).
Generally, short-wavelength visible light (for example, violet or blue light) is shallow in invasion depth into body tissue, while long-wavelength visible light (for example, red light) is deep in invasion depth into body tissue. In normal imaging using white illumination light containing long-wavelength light, an image including light reflected from a comparatively deep region of body tissue is observed. On the other hand, since short-wavelength light is used in special light imaging, an image of light reflected from a surface layer of the tissue is chiefly observed. Accordingly, the images observed by these two types of imaging differ from each other in spite of the same observed position. In use, those images are suitably switched from one to the other during endoscopic diagnosis.